This invention relates to a pipe coupling for coupling together a pipe having a liner pipe, hose or sleeve disposed therein to a second pipe member.
Until recently, pipes made from ferrous materials have been used for pipelines, and in particular mains pipelines, for conveying services such as gas and water. A substantial problem with such ferrous pipes has been their tendency to corrode over a period of several years' use leading to loss of integrity of the pipe wall. One solution to this problem has to been to provide a liner pipe, hose or sleeve formed from a suitable material, for example a plastics material such as polyethylene, or an elastomeric material. In order to undertake a pipe lining operation, it is necessary to dig a trench at either end of the ferrous pipe section to be repaired, the liner being pulled through the host pipe bore such that eventually its end protrudes beyond the ferrous pipe end. In order to ensure that the joint is fluid tight, it is then necessary to provide a mechanical seal between the pressure-containing plastics liner and the pipe or fitting to which it is connected, and it is also necessary to provide a mechanical seal between the plastics liner pipe and the host pipe against the ingress of ground water, and a gripping means for preventing retraction of the liner pipe into the host pipe.
It is an object of the present invention to provide such a pipe coupling.